General Management of Poisoned Patients

1. General Management of Poisoned Patients PWM OLLY INDRAJANI 2013

2. Introduction

3. Poisoningoccurs when exposure to a substance adversely affects the function of any system within an organism. • The setting of the poison exposure may be occupational, environmental, recreational, or medicinal.

4. Poisoning may result from varied portals of entry, including - inhalation, - insufflation, - ingestion, - cutaneous - mucous membrane exposure, and - injection. • Historically most poisonings have occurred when substances are tasted or swallowed

5. Toxins may be airborne in the form of gas or • vapors or in a suspension such as dust. • Caustics, vesicants, or irritants may directly • affect the skin, or a toxin may pass • transdermally and affect internal structures • (e.g., methylene chloride, aniline dye). • Parenteralexposure results from IV or SC • injection of medications or drugs of abuse

6. Resuscitation

11. Patients may have an altered mental status because of hypoxia, opioid intoxication, hypoglycemia, and Wernicke Encephalopathy, conditions readily treated by specific antidotes. • Empiric administration of antidotes (the "coma cocktail"), including supplemental oxygen, naloxone, glucose, and thiamine, should be considered after the medical history, vital signs, and immediately available laboratory data are taken into account

12. The dogma that the administration of thiamine should precede the administration of glucose to prevent the precipitation of acute Wernicke encephalopathy is unfounded. • Naloxone is a competitive opioid antagonist without any intrinsic toxicity that can be administered IV or IM and is appropriate to use in a hypoventilatingopioid-intoxicated patient who is not intubated. • Naloxone may be given to children as a therapeutic challenge when unintentional or intentional opioid exposure cannot be excluded.

13. Using miosis as the sole indication for naloxone administration is unreliable, because many other toxins can produce small pupils along with mental status depression, and some opioids classically leave pupil size unaltered (e.g., meperidine, propoxyphene). • Naloxone often completely reverses the effects of the opioid and restores effective ventilations and mental status for 20 to 60 minutes, so patients should be observed for 2 to 3 hours after IV administration

14. The risks of naloxone treatment are few but include the precipitation of an acute opioid withdrawal syndrome. • Although acute withdrawal is never life-threatening in adults, vomiting from withdrawal can result in aspiration. • Thus, the reflexive administration of large doses of naloxone should be discouraged

15. ED DiagnosisHistory

16. Toxicologic Physical Examination • Undress the patient completely. Check the patient's clothing for objects still retained in the pockets or substances hidden on the patient's body (waistband, groin, or between skinfolds) • Assess the general appearance of the patient and note any agitation, confusion, or obtundation. • Examine the skin for cyanosis or flushing, excessive diaphoresis or dryness, signs of injury or injection, ulcers, or bullae. • Bruising may be a clue to trauma, a prolonged duration of unconsciousness, or coagulopathy.

17. Toxicologic Physical Examination • Examine the eyes for pupil size, reactivity, nystagmus, dysconjugate gaze, or excessive lacrimation. • Examine the oropharynxfor hypersalivation or excessive dryness. Auscultatethe lung fields to assess for bronchorrhea or wheezing, and the heart for its rhythm, rate, and regularity. • Examine the abdomen, noting the presence of bowel sounds, enlarged bladder, and abdominal tenderness or rigidity. Evaluate the extremities for muscle tone and note any tremor or fasciculation

18. Toxidromes

21. Toxicologic Screen

23. General Decontamination • The general approach to most toxic exposures  the removal of the patient from the substance and the substance from the patient. • Toxins on the outside of the body washed away. • Toxins within the body, either bound within the gut lumen to make it unavailable for absorption or  elimination from the gut, blood, or tissues can be enhanced.

24. Gross Decontamination • Surface decontamination is achieved by completely undressing patients and thoroughly washing them with copious amounts of water. Patients requiring assistance should be attended to by properly gowned staff. • The towels used to dry patients and patients' clothing, shoes, socks, watches, and jewelry should be handled as contaminated material. • If possible, surface decontamination should occur prior to the patient's entry into the ED or other areas in the hospital. • In mass casualty exposures, this typically occurs at a staging area adjacent to the ED

26. GI Decontamination • The three general methods of decontamination: 1. Removingthe toxin from the stomach via the mouth 2. Bindingit inside the gut lumen 3. Enhancingtransit through the intestines • GI decontamination should never be initiated as a punitive action.

29. Toxin Adsorption in the GutActivated Charcoal

31. Enhancement of Bowel TransitCathartics

32. Whole-Bowel Irrigation • Whole-bowel irrigation is best accomplished by infusing the polyethylene glycol solution through a nasogastric tube, although in motivated patients, oral ingestion can be used. Typical doses are 1.5 to 2.0 L/h in adults, 1 L/h in children 6 to 12 years of age, and 0.5 L/h in children <6 years of age. • Contraindications include preceding diarrhea, ingestion of substances that are expected to result in significant diarrhea (except for heavy metals, because these substances do not adsorb well to activated charcoal), and bowel obstruction as evidenced by lack of bowel sounds. • Complications include bloating, cramping, and rectal irritation from frequent bowel movements.

35. Urinary Acidification • Acidification of urine can somewhat enhance elimination of weak bases, such as amphetamines, phencyclidine, and some other drugs. However, the risks, particularly in relation to rhabdomyolysis, far outweigh any benefits • Forced diuresishas never been shown to be effective for ingestion of any toxin, with the possible exception of chlorophenoxy herbicides when diuresis is combined with urinary alkalinization